# -*- coding: utf-8 -*- #
# Copyright 2023 Google LLC. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Utilities for working with volumes."""

import abc
import argparse
from typing import TypedDict

from googlecloudsdk.calliope import arg_parsers
from googlecloudsdk.calliope import base
from googlecloudsdk.command_lib.run import exceptions as serverless_exceptions

_supported_volume_types = {}

VolumeDict = TypedDict(
    'VolumeDict',
    {
        'name': str,
        'type': str,
        'read-only': str,
        'bucket': str,
        'location': str,
        'size-limit': str,
        'dynamic-mounting': str,
        'mount-options': str,
        'secret': str,
        'version': str,
        'path': str,
        'instances': str,
    },
    total=False,
)


def import_gapic_client_types():
  """Imports types from the v2 gapic client, handling potential gRPC import errors.

  Not all gCloud distributions have the gRPC library. Since only
  workerpools use the gapic client (which requires gRPC), we import it here
  so only workerpool commands are affected if gRPC is not installed.

  Returns:
    The run_v2 types module.
  """
  try:
    # pylint: disable=g-import-not-at-top
    from googlecloudsdk.generated_clients.gapic_clients.run_v2 import types
    # pylint: enable=g-import-not-at-top
    return types
  except ImportError:
    raise serverless_exceptions.NoGrpcInstalledError()


def _registered_volume_type(cls):
  """decorator for registering VolumeTypes.

  Only VolumeTypes with this decorator will be supported in add_volume

  Args:
    cls: the decorated class

  Returns:
    cls
  """
  _supported_volume_types[cls.name()] = cls
  return cls


def add_volume(volume, volumes, messages, release_track):
  """Add the volume described by the given volume dict to the resource."""
  _validate_volume_name_and_type(volume, release_track)
  new_vol = messages.Volume(name=volume['name'])
  vol_type = _supported_volume_types[volume['type']]
  vol_type.validate_volume_add(volume, release_track)
  vol_type.validate_fields(volume, release_track)
  vol_type.fill_volume(volume, new_vol, messages)

  volumes[volume['name']] = new_vol


def create_volume_v2(
    volume: VolumeDict,
    release_track: base.ReleaseTrack = base.ReleaseTrack.ALPHA,
):
  """Create the volume described by the given volume dict to the resource."""
  types = import_gapic_client_types()
  _validate_volume_name_and_type(volume, release_track)
  vol_type = _supported_volume_types[volume['type']]
  vol_type.validate_volume_add(volume, release_track)
  vol_type.validate_fields(volume, release_track)

  return vol_type.create_volume_v2(volume, types)


def volume_help(release_track):
  """Generates the help text for all registered volume types."""
  hlp = []
  for _, volume_type in sorted(
      _supported_volume_types.items(), key=lambda t: t[0]
  ):
    if release_track in volume_type.release_tracks():
      hlp.append(volume_type.generate_help(release_track))

  return '\n\n'.join(hlp)


class _VolumeType(abc.ABC):
  """Base class for supported volume types.

  To add a new supported volume type, create a subclass of this type,
  implement all the abstract methods, and annotate the class with
  @_registered_volume_type.
  """

  @classmethod
  @abc.abstractmethod
  def name(cls):
    """The name of this Volume type.

    This is the string that will need to be provided as the `type` value in the
    add volumes flag to use this type of volume.
    """
    pass

  @classmethod
  @abc.abstractmethod
  def help(cls):
    """Help text for this volume type."""
    pass

  @classmethod
  def release_tracks(cls):
    """The list of release tracks that this volume type should be present in.

    Used to progressively roll out types of volumes.

    Returns:
      A list of base.ReleaseTrack
    """
    return base.ReleaseTrack.AllValues()

  @classmethod
  @abc.abstractmethod
  def required_fields(cls, release_track):
    """A dict of field_name: help text for all fields that must be present."""
    return {}

  @classmethod
  @abc.abstractmethod
  def optional_fields(cls, release_track):
    """A dict of field_name: help text for all fields that are optional."""
    return {}

  @classmethod
  @abc.abstractmethod
  def fill_volume(cls, volume, new_vol, messages):
    """Fills in the Volume message (V1) from the provided volume dict."""
    pass

  @classmethod
  @abc.abstractmethod
  def create_volume_v2(cls, volume):
    """Creates the volume (V2) from the provided volume dict."""
    pass

  @classmethod
  @abc.abstractmethod
  def validate_fields(cls, volume, release_track):
    """Validate any additional constraints on the volume type."""
    pass

  @classmethod
  def validate_volume_add(cls, volume, release_track=base.ReleaseTrack.GA):
    """Validate that the volume dict has all needed parameters for this type."""
    required_keys = set(cls.required_fields(release_track).keys())
    optional_keys = set(cls.optional_fields(release_track).keys())
    for key in volume:
      if key == 'name':
        continue
      elif key == 'type':
        if volume[key] != cls.name():
          raise serverless_exceptions.ConfigurationError(
              'expected volume of type {} but got {}'.format(
                  cls.name(), volume[key]
              )
          )
      elif key not in required_keys and key not in optional_keys:
        raise serverless_exceptions.ConfigurationError(
            'Volume {} of type {} had unexpected parameter {}'.format(
                volume['name'], volume['type'], key
            )
        )
    missing = required_keys - volume.keys()
    if missing:
      raise serverless_exceptions.ConfigurationError(
          'Volume {} of type {} requires the following parameters: {}'.format(
              volume['name'], volume['type'], missing
          )
      )

  @classmethod
  def generate_help(cls, release_track):
    """Generate help text for this volume type."""
    required_fields = '\n'.join(
        '* {}: (required) {}  '.format(name, hlp)
        for name, hlp in cls.required_fields(release_track).items()
    )
    required = f'\n{required_fields}  ' if required_fields.strip() else ''
    optional_fields = '\n'.join(
        '* {}: (optional) {}  '.format(name, hlp)
        for name, hlp in cls.optional_fields(release_track).items()
        if name != 'name'
    )
    optional = f'\n{optional_fields}  ' if optional_fields.strip() else ''
    return '*{name}*: {hlp}\n  Additional keys:  {required}{optional}  '.format(
        name=cls.name(),
        hlp=cls.help(),
        required=required,
        optional=optional,
    )


@_registered_volume_type
class _InMemoryVolume(_VolumeType):
  """Volume Type representing an in-memory emptydir."""

  @classmethod
  def name(cls):
    return 'in-memory'

  @classmethod
  def help(cls):
    return (
        "An ephemeral volume that stores data in the instance's memory. "
        'With this type of volume, data is not shared between instances and '
        'all data will be lost when the instance it is on is terminated.'
    )

  @classmethod
  def release_tracks(cls):
    return base.ReleaseTrack.AllValues()

  @classmethod
  def required_fields(cls, release_track):
    return {}

  @classmethod
  def optional_fields(cls, release_track):
    if release_track != base.ReleaseTrack.GA:
      return {
          'name': (
              'The name of the volume. A name will be generated if the'
              ' `mount-path` flag is specified. A name is required if'
              ' `mount-path` is not specified.'
          ),
          'mount-path': (
              'The path at which the volume should be mounted. The `mount-path`'
              ' parameter is only supported for single container services which'
              ' do not make use of the --container flag. For multi-container'
              ' services, specify the `mount-path` parameter under the'
              ' --add-volume-mount flag.'
          ),
          'size-limit': (
              'A quantity representing the maximum amount of memory allocated'
              ' to this volume, such as "512Mi" or "3G". Data stored in an'
              ' in-memory volume consumes the memory allocation of the'
              ' container that wrote the data. If size-limit is not specified,'
              ' the maximum size will be half the total memory limit of all'
              ' containers.'
          ),
      }
    return {
        'size-limit': (
            'A quantity representing the maximum amount of memory allocated to'
            ' this volume, such as "512Mi" or "3G". Data stored in an in-memory'
            ' volume consumes the memory allocation of the container that wrote'
            ' the data. If size-limit is not specified, the maximum size will'
            ' be half the total memory limit of all containers.'
        )
    }

  @classmethod
  def fill_volume(cls, volume, new_vol, messages):
    if 'size-limit' in volume:
      src = messages.EmptyDirVolumeSource(
          medium='Memory', sizeLimit=volume['size-limit']
      )
    else:
      src = messages.EmptyDirVolumeSource(medium='Memory')
    new_vol.emptyDir = src

  @classmethod
  def create_volume_v2(cls, volume, types):
    source = types.EmptyDirVolumeSource(
        medium=types.EmptyDirVolumeSource.Medium.MEMORY
    )
    if 'size-limit' in volume:
      source.size_limit = volume['size-limit']
    return types.Volume(
        name=volume['name'],
        empty_dir=source,
    )


@_registered_volume_type
class _TempDiskVolume(_VolumeType):
  """Volume Type representing a disk-backed emptydir."""

  @classmethod
  def name(cls):
    return 'ephemeral-disk'

  @classmethod
  def help(cls):
    return (
        'A volume that stores data on a temporary disk. '
        'With this type of volume, data is not shared between instances and '
        'all data will be lost when the instance it is on is terminated.'
    )

  @classmethod
  def release_tracks(cls):
    return [base.ReleaseTrack.ALPHA]

  @classmethod
  def required_fields(cls, release_track):
    return {}

  @classmethod
  def optional_fields(cls, release_track):
    return {
        'name': (
            'The name of the volume. A name will be generated if the'
            ' `mount-path` flag is specified. A name is required if'
            ' `mount-path` is not specified.'
        ),
        'mount-path': (
            'The path at which the volume should be mounted. The `mount-path`'
            ' parameter is only supported for single container services which'
            ' do not make use of the --container flag. For multi-container'
            ' services, specify the `mount-path` parameter under the'
            ' --add-volume-mount flag.'
        ),
        'size': (
            'A quantity representing the amount of disk space allocated to'
            ' this volume, such as "512Mi" or "3G".'
        )
    }

  @classmethod
  def fill_volume(cls, volume, new_vol, messages):
    if 'size' in volume:
      src = messages.EmptyDirVolumeSource(
          medium='Disk', sizeLimit=volume['size']
      )
    else:
      src = messages.EmptyDirVolumeSource(medium='Disk')
    new_vol.emptyDir = src


@_registered_volume_type
class _NfsVolume(_VolumeType):
  """Volume Type representing an NFS volume."""

  @classmethod
  def name(cls):
    return 'nfs'

  @classmethod
  def help(cls):
    return 'Represents a volume backed by an NFS server.'

  @classmethod
  def required_fields(cls, release_track):
    return {
        'location': 'The location of the NFS Server, in the form SERVER:/PATH'
    }

  @classmethod
  def optional_fields(cls, release_track):
    if release_track != base.ReleaseTrack.GA:
      return {
          'name': (
              'The name of the volume. A name will be generated if the'
              ' `mount-path` flag is specified. A name is required if'
              ' `mount-path` is not specified.'
          ),
          'mount-path': (
              'The path at which the volume should be mounted. The `mount-path`'
              ' parameter is only supported for single container services which'
              ' do not make use of the --container flag. For multi-container'
              ' services, specify the `mount-path` parameter under the'
              ' --add-volume-mount flag.'
          ),
          'readonly': (
              'A boolean. If true, this volume will be read-only from all'
              ' mounts.'
          ),
      }
    return {
        'readonly': (
            'A boolean. If true, this volume will be read-only from all mounts.'
        )
    }

  @classmethod
  def validate_fields(cls, volume, release_track):
    location = volume['location']
    if ':/' not in location:
      raise serverless_exceptions.ConfigurationError(
          "Volume {}: field 'location' must be of the form"
          ' IP_ADDRESS:/DIRECTORY'.format(volume['name'])
      )

  @classmethod
  def fill_volume(cls, volume, new_vol, messages):
    readonly = _is_readonly(volume)
    server, path = volume['location'].split(':/', 1)
    # need to re-add leading slash
    path = '/' + path
    src = messages.NFSVolumeSource(server=server, path=path, readOnly=readonly)
    new_vol.nfs = src

  @classmethod
  def create_volume_v2(cls, volume, types):
    readonly = _is_readonly(volume)
    location = volume['location']
    server, path = str(location).split(':/', 1)
    # need to re-add leading slash
    path = '/' + path
    return types.Volume(
        name=volume['name'],
        nfs=types.NFSVolumeSource(
            server=server,
            path=path,
            read_only=readonly,
        ),
    )


@_registered_volume_type
class _GcsVolume(_VolumeType):
  """Volume Type representing a GCS volume."""

  @classmethod
  def name(cls):
    return 'cloud-storage'

  @classmethod
  def help(cls):
    return (
        'A volume representing a Cloud Storage bucket. This volume '
        'type is mounted using Cloud Storage FUSE. See '
        'https://cloud.google.com/storage/docs/gcs-fuse for the details '
        'and limitations of this filesystem.'
    )

  @classmethod
  def validate_fields(cls, volume, release_track):
    if release_track == base.ReleaseTrack.ALPHA:
      try:
        bool_parser = arg_parsers.ArgBoolean()
        dynamic_mounting = bool_parser(volume.get('dynamic-mounting', 'false'))
      except argparse.ArgumentTypeError:
        raise serverless_exceptions.ConfigurationError(
            'dynamic-mounting must be set to true or false.'
        )
      if (dynamic_mounting and 'bucket' in volume) or (
          not dynamic_mounting and 'bucket' not in volume
      ):
        raise serverless_exceptions.ConfigurationError(
            'Either set bucket or enable dynamic-mounting, not both.'
        )

  @classmethod
  def required_fields(cls, release_track):
    if release_track == base.ReleaseTrack.ALPHA:
      return {}
    return {
        'bucket': 'the name of the bucket to use as the source of this volume'
    }

  @classmethod
  def optional_fields(cls, release_track):
    fields = {
        'readonly': (
            'A boolean. If true, this volume will be read-only from all mounts.'
        ),
        'mount-options': (
            'A list of flags to pass to GCSFuse. Flags '
            + 'should be specified without leading dashes and separated by '
            + 'semicolons.'
        ),
    }

    if release_track == base.ReleaseTrack.ALPHA:
      fields['bucket'] = (
          'the name of the bucket to use as the source of this volume.'
      )
      fields['dynamic-mounting'] = (
          'A boolean. If true, the volume will be mounted dynamically. '
          + 'Note: You will either need to specify a bucket or set '
          + 'dynamic-mounting to true, but not both.'
      )
    if release_track != base.ReleaseTrack.GA:
      fields['name'] = (
          'The name of the volume. A name will be generated if the'
          ' `mount-path` flag is specified. A name is required if'
          ' `mount-path` is not specified.'
      )
      fields['mount-path'] = (
          'The path at which the volume should be mounted. The `mount-path`'
          ' parameter is only supported for single container services which'
          ' do not make use of the --container flag. For multi-container'
          ' services, specify the `mount-path` parameter under the'
          ' --add-volume-mount flag.'
      )
    return fields

  @classmethod
  def fill_volume(cls, volume, new_vol, messages):
    src = messages.CSIVolumeSource(
        driver='gcsfuse.run.googleapis.com', readOnly=_is_readonly(volume)
    )
    src.volumeAttributes = messages.CSIVolumeSource.VolumeAttributesValue()
    if 'bucket' in volume:
      src.volumeAttributes.additionalProperties.append(
          messages.CSIVolumeSource.VolumeAttributesValue.AdditionalProperty(
              key='bucketName', value=volume['bucket']
          )
      )
    if 'mount-options' in volume:
      src.volumeAttributes.additionalProperties.append(
          messages.CSIVolumeSource.VolumeAttributesValue.AdditionalProperty(
              key='mountOptions',
              value=volume['mount-options'].replace(';', ','),
          )
      )
    if 'dynamic-mounting' in volume and volume['dynamic-mounting']:
      src.volumeAttributes.additionalProperties.append(
          messages.CSIVolumeSource.VolumeAttributesValue.AdditionalProperty(
              key='bucketName', value='_'
          )
      )
    new_vol.csi = src

  @classmethod
  def create_volume_v2(cls, volume, types):
    if 'mount-options' in volume:
      mount_options = volume['mount-options'].split(';')
    else:
      mount_options = []
    source = types.GCSVolumeSource(
        read_only=_is_readonly(volume),
        mount_options=mount_options,
    )
    # If dynamic mounting is enabled, we need to set the bucket to a special
    # value to indicate that the bucket should be dynamically mounted.
    if 'dynamic-mounting' in volume and volume['dynamic-mounting']:
      source.bucket = '_'
    else:
      source.bucket = volume['bucket']
    return types.Volume(
        name=volume['name'],
        gcs=source,
    )


@_registered_volume_type
class SecretVolume(_VolumeType):
  """Represents a secret as a volume."""

  @classmethod
  def release_tracks(cls):
    return [base.ReleaseTrack.ALPHA]

  @classmethod
  def name(cls):
    return 'secret'

  @classmethod
  def help(cls):
    return 'Represents a secret stored in Secret Manager as a volume.'

  @classmethod
  def required_fields(cls, release_track):
    return {
        'secret': (
            'The name of the secret in Secret Manager. Must be a secret in the'
            ' same project being deployed or be an alias mapped in the'
            ' `run.googleapis.com/secrets` annotation.'
        ),
        'version': 'The version of the secret to make available in the volume.',
        'path': 'The relative path within the volume to mount that version.',
    }

  @classmethod
  def optional_fields(cls, release_track):
    return {
        'name': (
            'The name of the volume. A name will be generated if the'
            ' `mount-path` flag is specified. A name is required if'
            ' `mount-path` is not specified.'
        ),
        'mount-path': (
            'The path at which the volume should be mounted. The `mount-path`'
            ' parameter is only supported for single container services which'
            ' do not make use of the --container flag. For multi-container'
            ' services, specify the `mount-path` parameter under the'
            ' --add-volume-mount flag.'
        ),
    }

  @classmethod
  def fill_volume(cls, volume, new_vol, messages):
    src = messages.SecretVolumeSource(secretName=volume['secret'])
    item = messages.KeyToPath(path=volume['path'], key=volume['version'])
    src.items.append(item)
    new_vol.secret = src

  @classmethod
  def create_volume_v2(cls, volume, types):
    return types.Volume(
        name=volume['name'],
        secret=types.SecretVolumeSource(
            secret=volume['secret'],
            items=[
                types.VersionToPath(
                    version=volume['version'], path=volume['path']
                )
            ],
        ),
    )


@_registered_volume_type
class CloudSqlInstance(_VolumeType):
  """Represents a Cloud SQL instance as a volume."""

  @classmethod
  def release_tracks(cls):
    return [base.ReleaseTrack.ALPHA]

  @classmethod
  def name(cls):
    return 'cloudsql'

  @classmethod
  def help(cls):
    return 'Represents a Cloud SQL instance as a volume.'

  @classmethod
  def validate_fields(cls, volume, release_track):
    for instance in volume['instances'].split(';'):
      instance = instance.strip().split(':')
      if len(instance) != 3:
        raise serverless_exceptions.ConfigurationError(
            'Cloud SQL instances must be in the form'
            ' project_id:region:instance_id'
        )

  @classmethod
  def required_fields(cls, release_track):
    return {
        'instances': (
            'The name of the Cloud SQL instances to mount. Must be in the form'
            ' project_id:region:instance_id and separated by semicolons.'
        ),
    }

  @classmethod
  def optional_fields(cls, release_track):
    if release_track != base.ReleaseTrack.GA:
      return {
          'name': (
              'The name of the volume. A name will be generated if the'
              ' `mount-path` flag is specified. A name is required if'
              ' `mount-path` is not specified.'
          ),
          'mount-path': (
              'The path at which the volume should be mounted. The `mount-path`'
              ' parameter is only supported for single container services which'
              ' do not make use of the --container flag. For multi-container'
              ' services, specify the `mount-path` parameter under the'
              ' --add-volume-mount flag.'
          ),
      }
    return {}

  @classmethod
  def fill_volume(cls, volume, new_vol, messages):
    src = messages.CSIVolumeSource(driver='cloudsql.run.googleapis.com')
    src.volumeAttributes = messages.CSIVolumeSource.VolumeAttributesValue()
    if 'instances' in volume:
      src.volumeAttributes.additionalProperties.append(
          messages.CSIVolumeSource.VolumeAttributesValue.AdditionalProperty(
              key='instances',
              value=volume['instances'].replace(';', ','),
          )
      )
    new_vol.csi = src

  @classmethod
  def create_volume_v2(cls, volume, types):
    return types.Volume(
        name=volume['name'],
        cloud_sql_instance=types.CloudSqlInstance(
            instances=[
                instance.strip() for instance in volume['instances'].split(';')
            ]
        ),
    )


def _is_readonly(volume):
  return 'readonly' in volume and volume['readonly'].lower() == 'true'


def _validate_volume_name_and_type(volume, release_track):
  """Validates the volume name and type."""
  if release_track != base.ReleaseTrack.GA:
    if 'type' not in volume:
      raise serverless_exceptions.ConfigurationError(
          'All added volumes must have a type'
      )
    # Volume name should have already been generated if the user specified the
    # `mount-path` flag.
    if 'name' not in volume:
      raise serverless_exceptions.ConfigurationError(
          'Volume "name" must be specified if "mount-path" is not specified.'
      )
  else:
    if 'name' not in volume or 'type' not in volume:
      raise serverless_exceptions.ConfigurationError(
          'All added volumes must have a name and type'
      )

  if volume['type'] not in _supported_volume_types:
    raise serverless_exceptions.ConfigurationError(
        'Volume type {} not supported'.format(volume['type'])
    )
  vol_type = _supported_volume_types[volume['type']]
  if release_track not in vol_type.release_tracks():
    raise serverless_exceptions.ConfigurationError(
        'Volume type {} not supported'.format(volume['type'])
    )
